Example: Kubota 7060 has 71 engine hp and a 4-cylinder 203 CID engine. Chevrolet made a 250 6-cylinder that produced 155 hp that they put in their pickup truck. What's the deal?
General Question: Why are tractor engines so small?
- Thread starter mbu
- Start date
The 2.2 L turbocharged 86 lebaron had 95 hp, 65 naturally aspirated.
The diesel by comparison is far more fuel efficient compared to a gasoline engine of similar displacement.
Dodge 225 slant 6 engines ran in swathers for many years. Chrysler flathead 6 engines were used in a few combines. My cockshutt 40 gas is a large 6 cylinder engine.
Statistics will be all over the map, but fuel consumption speaks for itself.
The diesel by comparison is far more fuel efficient compared to a gasoline engine of similar displacement.
Dodge 225 slant 6 engines ran in swathers for many years. Chrysler flathead 6 engines were used in a few combines. My cockshutt 40 gas is a large 6 cylinder engine.
Statistics will be all over the map, but fuel consumption speaks for itself.
I believe that we would find that those small diesel engines are designed to produce torque and not speed. The tractor frame actually limits the amount of force produced by the engine as too much power with some implements will damage the frame.
There is a reason that people buy "heavy" tractors that can withstand the push, pull, and torque that diesel engines and implements lay on those frames.
Horsepower produces speed, but torque produces force.
The engines don't have to be small, but the tractor strength and weight must go up to withstand those larger engines.
The hydraulic pump does not require all the power that a tractor engine produces, but the hydraulic pump output pressure and internal diameter of the actuators are reduced for the same reason.
There is a reason that people buy "heavy" tractors that can withstand the push, pull, and torque that diesel engines and implements lay on those frames.
Horsepower produces speed, but torque produces force.
The engines don't have to be small, but the tractor strength and weight must go up to withstand those larger engines.
The hydraulic pump does not require all the power that a tractor engine produces, but the hydraulic pump output pressure and internal diameter of the actuators are reduced for the same reason.
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Torque and gearing help do the work. I am remember running the dyno at work and 170 horsepower tractors putting out 1200+ of torque!
Pat
Pat
CountryBumkin
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I sounds like the question you meant to ask is why the tractors don't put out more Hp for their displacement. Tractors are designed to run at WOT for extended periods of time, so you need them to be fuel efficient and durable running wide open. Because of this, they generally run somewhere between 2-3k rpms at WOT. Cars are not designed to run wide open for extended periods of time, so their peak HP usually happens beween 3-5k rpms. Diesel trucks may be lower.
dandeman
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BX2230, LA211 FEL, RCK60B Mower, GCK60BX Bagger; Ford 4000, bush hog, blade, etc
Ditto.. posts above...
Tractor engines are long stroke engines to give high torque, which the long stroke also limits max rpm to around 2800, which again is better suited to the requirements in a tractor.
I use to joke that tractor and piston aviation engines are kin, other than light weight metals used to build aviation engines. Propeller aircraft aviation engines similar to tractors need to limit rpm (using long stroke design) to around 2200-2400 rpm to keep propeller tips from getting too close to speed of sound (efficiency falls rapidly). And, like tractor engines, need to be able to run at full throttle for long periods of time.
Car engines typically only run at full throttle for seconds at a time... short stroke engines running much higher rpm to get that amount of HP.
Another example of this was a continuous duty ONAN generator I had.. 25 cu in displacement single cylinder 1800rpm engine rated at only 5HP. My old Gilson lawn tractor had a single cylinder Briggs & Stratton 25 cu in engine rated at 16 HP running much higher rpm.. Guess which lasted the longest.
Can't resist..
Long stroke engines make earth shaking beautiful music.. whether it be airplane or tractor.. Loved the sound of a Continental 460 cu in flat six used in a Cessna 182 typically rated around 235HP depending on vintage.. non turbo charged version that is...
I remember reading years ago a NASA study of the smaller aviation piston engines i.e. the Lycomings and Continentals, regarding if a more efficient engine technology could be built in that power range.. Other than going to water cooling (which has it's own baggage), the study concluded the present designs are pretty much as good as it gets for that power application requirement range.
Tractor engines are long stroke engines to give high torque, which the long stroke also limits max rpm to around 2800, which again is better suited to the requirements in a tractor.
I use to joke that tractor and piston aviation engines are kin, other than light weight metals used to build aviation engines. Propeller aircraft aviation engines similar to tractors need to limit rpm (using long stroke design) to around 2200-2400 rpm to keep propeller tips from getting too close to speed of sound (efficiency falls rapidly). And, like tractor engines, need to be able to run at full throttle for long periods of time.
Car engines typically only run at full throttle for seconds at a time... short stroke engines running much higher rpm to get that amount of HP.
Another example of this was a continuous duty ONAN generator I had.. 25 cu in displacement single cylinder 1800rpm engine rated at only 5HP. My old Gilson lawn tractor had a single cylinder Briggs & Stratton 25 cu in engine rated at 16 HP running much higher rpm.. Guess which lasted the longest.
Can't resist..
Long stroke engines make earth shaking beautiful music.. whether it be airplane or tractor.. Loved the sound of a Continental 460 cu in flat six used in a Cessna 182 typically rated around 235HP depending on vintage.. non turbo charged version that is... I remember reading years ago a NASA study of the smaller aviation piston engines i.e. the Lycomings and Continentals, regarding if a more efficient engine technology could be built in that power range.. Other than going to water cooling (which has it's own baggage), the study concluded the present designs are pretty much as good as it gets for that power application requirement range.
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It's easy....
TORQUE IS REAL !!!!!!!!!!!!!!!!!!!!!!!
HP is FAKE !!!!!!!!!!!!!!!!!!!!! (sort of)
HP is something that James Watt invented to try to compare a steam engine to a plow horse. It contains a time factor. (So work over time) Because of that... you can have a 50cc 2-stroke dirt bike engine than makes 20 hp. (Spinning up over 20,000 rpm) Heck, that's more than my BX. But there's no way that little engine will push my tractor around, or run my hydro's. (unless you want to listen to that little thing scream)
Anyway... we need the torque, fuel efficiency, and low RPM's of a small diesel.
TORQUE IS REAL !!!!!!!!!!!!!!!!!!!!!!!
HP is FAKE !!!!!!!!!!!!!!!!!!!!! (sort of)
HP is something that James Watt invented to try to compare a steam engine to a plow horse. It contains a time factor. (So work over time) Because of that... you can have a 50cc 2-stroke dirt bike engine than makes 20 hp. (Spinning up over 20,000 rpm) Heck, that's more than my BX. But there's no way that little engine will push my tractor around, or run my hydro's. (unless you want to listen to that little thing scream)
Anyway... we need the torque, fuel efficiency, and low RPM's of a small diesel.
I haven't felt the need for my HP with my little 30hp B2910. I've needed more weight, but not more HP.
My grandparents farm had all 1930's - 40's John Deere tractors when I was a kid. The main work tractor was the Model A and G.
John Deere A
Drawbar (claimed): 18 hp [13.4 kW]
Belt (claimed): 24 hp [17.9 kW]
Plows: 2*14-inch
Drawbar (tested): 18.72 hp [14.0 kW]
PTO (tested): 23.63 hp [17.6 kW]
It did it all with about the same, actually less HP, than my Kubota B2620. The big tractor on the farm was the G, it had a little more power.
John Deere A
Drawbar (claimed): 18 hp [13.4 kW]
Belt (claimed): 24 hp [17.9 kW]
Plows: 2*14-inch
Drawbar (tested): 18.72 hp [14.0 kW]
PTO (tested): 23.63 hp [17.6 kW]
It did it all with about the same, actually less HP, than my Kubota B2620. The big tractor on the farm was the G, it had a little more power.
Aren't always so small... I have a 22hp tractor with a 425 cubic inch 4 cylinder in it, but it makes that power wide open throttle governed at only 1,100 rpm...
I also have one with a 382 4 cyl that makes 15 hp at 1,050 rpm and a 403 4 cyl making 26hp at 1,100 rpm.
Tractor engines aren't so much about horse power as they are about torque and where they make the torque.
I also have one with a 382 4 cyl that makes 15 hp at 1,050 rpm and a 403 4 cyl making 26hp at 1,100 rpm.
Tractor engines aren't so much about horse power as they are about torque and where they make the torque.
Nice tractor MaleHoe!
Okay, back to the topic...
Kubota M7060 Diesel 4 cylinder 203 CID rated at 71 hp, turbo charged.
Kubota M6060 Diesel 4 cylinder 203 CID rated at 63.3 hp, turbo charged.
Why the difference?
Okay, back to the topic...
Kubota M7060 Diesel 4 cylinder 203 CID rated at 71 hp, turbo charged.
Kubota M6060 Diesel 4 cylinder 203 CID rated at 63.3 hp, turbo charged.
Why the difference?
First off not to many companies will make a one off engine for an application! Parts redundancy for cost savings!
The difference will be done through the fuel systems by de-tuning smaller by injector size. It could done by the computer program.
Case in point my Alero has 3.4 liter @170 hp the same displacement engine the same year in the minivan has 210 hp.
Pat
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I'm new to Kubota's, but most domestic's get at least 2 sizes of tractors out of each engine, and some of them got 2 or 3 displacement sizes out of the same block. In IH, everything from the 966/986 to the 1566/86 had the same block, and they used a larger displacement version on their trucks.
HP is kind of a gray zone in tractors. PTO hp and drawbar power are what matters. My little 24hp B7610 pulled a crew cab F150 up a hill in HI range at 1800 rpms without any chugging.
My only concern with HP is resale for people who only care about that number.
My only concern with HP is resale for people who only care about that number.
Hp for tractor in your photo built in mid to late 40's maybe to early 50's is more than HP you listed for the JD A tested on Jan. 1,1934 when Nebraska test was performed. JD produces tractor models today with a 4.5L(276 cid) that can reach 100 hp or a little more.
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rednecklimo85
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78 B6100E(brush hog, boxblade, snowplow) 85 B7200DT(loader and backhoe)
Really hard to compare engines based on HP only. My 14hp B6100 has way more power then it does traction, regardless of how much weight i put on it. My 23 HP Lawn tractor on the other hand, couldn't pull an ant from a mole hill. Same thing with a new 22HP SCUT that I borrowed, just didn't have the same kind of pulling power.
This is why you saw HP numbers disappear from snow blowers and you started to see displacement or torque. Manufactures were inflating numbers in their favor.
This is why you saw HP numbers disappear from snow blowers and you started to see displacement or torque. Manufactures were inflating numbers in their favor.
My late 80's B6200 is rated at 15hp. and people are amazed at the work it can do . . . and do it all day!! Hell I'm impressed with it as well. 2500 seems to be the sweet spot for this one, but it has a little more on tap just in case.
This tractor @240hp. has an engine about the size of my Coleman cooler - I'm impressed. That's my wagon in the background . . .
This tractor @240hp. has an engine about the size of my Coleman cooler - I'm impressed. That's my wagon in the background . . .
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That's why tractors have 3 different hp ratings.
Gross HP (what the engine is rated at)
PTO HP (HP available to drive shaft powered implements)
Drawbar HP (actual tractive force available to pull implements)
You rarely see the drawbar ratings anymore. In the old days all tractors were subjected to the Nebraska Tests and the numbers were published. You have to make sure you have the right HP rating for the tasks you intend to perform.